is it really necessary?

Who is secure about their weight? Even the girl who works out 3 times a week at the gym would be insecure about her weight. Check out this advertising campaign for a fitness company where they changed the busstop seat to a weighing machine.

*you are now officially a laughing stock*
'i will hate you for the rest of my life FitnessFirst!' swears the cow in red

It might be creative but i'd say in a -ve way. Showing pictures of fit and beautiful people to inspire customers to join and keep fit is one thing. Publicly humiliating your potential customer is another. Not only is this ad campaign expensive (rigging up the whole thing across the nation cannot be any cheap), it is also insensitive.